An earthquake has a single magnitude. The shaking that it causes has many values that vary from place to place based on distance, type of surface material, and other factors. See the Intensity section below for more details on shaking intensity measurements.
Does the Mercalli scale measure energy?
The Mercalli Intensity Scale measures the intensity of an earthquake by observing its effect on people, the environment and the earth's surface. The Richter Scale measures the energy released by an earthquake using a seismograph.
What does the Mercalli Intensity Scale?
The effect of an earthquake on the Earth's surface is called the intensity. The intensity scale consists of a series of certain key responses such as people awakening, movement of furniture, damage to chimneys, and finally - total destruction.
What does the Mercalli scale not tell you?
The Mercalli intensity scale (or more precisely the Modified Mercalli intensity scale) is a scale to measure the intensity of earthquakes. Unlike with the Richter scale, the Mercalli scale does not take into account energy of an earthquake directly.
What's the difference between the Mercalli and Richter scale?
While the Mercalli scale describes the intensity of an earthquake based on its observed effects, the Richter scale describes the earthquake's magnitude by measuring the seismic waves that cause the earthquake.
What are the disadvantages of the Richter scale?
Disadvantages of Richter Scale Earthquakes can cause subsidence, or the lowering of the ground surface. This can cause coastal areas to be permanently flooded. Lateral spreading can also occur, wherein sloping ground moves downhill, opening up cracks.
Why is the Richter scale inaccurate?
Because of limitations imposed by seismographs and the emphasis on measuring a single peak amplitude, the Richter scale underestimates the energy released in earthquakes with magnitudes greater than 6.5, since the values calculated after measuring very large seismic waves tend to cluster, or “saturate,” near one ...
Why is the Mercalli scale subjective?
The Mercalli intensity scale tends to be very subjective and thus is generally only used for historical earthquakes that were near people but were not recorded by seismometers. Why might the Mercalli scale be subjective? It relies on testimony from people. It does not take into account distance.
What is the Mercalli intensity scale?
Explanation: The Mercalli Intensity Scale is a method of measuring earthquake intensity. It measures the damage from earthquakes and the observed effects.
Is modified Mercalli intensity scale still used?
The Modified Mercalli Intensity Scale is still used today and can be found in the image below.
What is the modified Mercalli scale?
The Modified Mercalli Intensity Scale of 1931 is the basis for the U.S. evaluation of seismic intensity. Intensity is different than the magnitude in that it is based on observations of the effects and damage of an earthquake, not on scientific measurements.
How many divisions are there in the Mercalli scale?
The Mercalli scale has 12 divisions, using Roman numerals from I to XII. I. Not felt except by a very few under especially favorable circumstances. II. Felt only by a few persons at rest, especially on upper floors of buildings. Delicately suspended objects may swing. III.
Is the correlation between magnitude and intensity weak?
Although the correlation between magnitude and intensity is weak, the USGS has made a pretty good estimate of the intensity that might be felt near the epicenter of an earthquake of a specific magnitude.
Is an earthquake felt indoors?
III. Felt quite noticeably indoors, especially on upper floors of buildings, but many people do not recognize it as an earthquake. Standing motorcars may rock slightly. Vibration like passing truck. Duration estimated.
What is the difference between the Mercalli scale and the Richter scale?
While the Mercalli scale describes the intensity of an earthquake based on its observed effects, the Richter scale describes the earthquake's magnitude by measuring the seismic waves that cause the earthquake. The two scales have different applications and measurement techniques.
Why is the Richter scale used?
It is, however, used to compare the damage caused by earthquakes in different areas. The Richter scale is used to measure the magnitude of most modern earthquakes and allows scientists to accurately compare the strength of earthquakes at different times and locations.
How does the Mercalli scale measure earthquake intensity?
The Mercalli Intensity Scale measures the intensity of an earthquake by observing its effect on people, the environment and the earth’s surface.
When was the modified Mercalli scale created?
It is known today as the Modified Mercalli Intensity Scale. The Richter Magnitude Scale was developed in 1935 by Charles Richter. It was initially created to study a particular area in California, using the Wood-Anderson torsion seismograph, to compare the size of different earthquakes in the region.
Is the Mercalli scale linear or logarithmic?
The Mercalli scale is linear and the Richter scale is logarithmic. i.e. a magnitude 5 earthquake is ten times as intense as a magnitude 4 earthquake.
Who developed the Mercalli intensity scale?
History. The Mercalli Intensity Scale was developed by Italian volcanologist Giuseppe Mercalli in 1884 and expanded to include 12 degrees of intensity in 1902 by Adolfo Cancani. It was modified again by Harry O. Wood and Frank Neumann in 1931. It is known today as the Modified Mercalli Intensity Scale.
Is a 3.0 earthquake stronger than a 2.0 earthquake?
A 3.0 earthquake is 10 times stronger than a 2.0 earthquake. Consistency. Varies depending on distance from epicenter. Varies at different distances from the epicenter, but one value is given for the earthquake as a whole. Richter Scale reading of 2011 Tōhoku earthquake (it was followed by a tsunami)
